Acids and Bases Lecture Notes

Introduction

• Acids and bases are integral to many products and processes:
  • Foods, soaps, detergents, fertilizers, explosives, dyes, plastics, pesticides, paper
• Biological relevance:
  • Stomach acidity
  • Blood's basicity
  • Amino acids in proteins
  • Genetic code bases (A, T, C, G)

Historical Perspective

• Ancient Greeks defined acids and bases by behavior, not molecular structure:
  • Acids tasted sour and corroded metal.
  • Bases felt slippery and counteracted acids.

Molecular Interaction in Water

• Molecules exchange protons (H+ ions) and electrons in water.
• Protons (H+): positively charged
• Electrons (e-): negatively charged

Molecular Reactions

• Proton Donors:
  • Molecules giving up protons become more negatively charged.
• Proton Acceptors:
  • Molecules accepting protons or giving up electrons become more positively charged.

Strong vs. Weak Acids/Bases

• Strong Acids: Aggressively donate protons to water.
• Strong Bases: Aggressively accept protons from water.
• Weak Acids/Bases:
  • Donate or accept few protons.
  • Reach equilibrium with minimal molecular exchange.
  • Examples:
    • Vinegar (weak acid)
    • Ammonia (weak base)

Role of Water

• Acts as both acid and base:
  • Facilitates proton exchange
  • Neutralization: When acids and bases cancel out their effects
• Water is considered a resilient and fair medium for acid-base reactions.

Conclusion

• Acids, bases, and water play crucial roles in chemical reactions.
• Water is a neutral participant enabling balanced chemical exchanges.

Note: Additional details on acid-base reactions outside water were mentioned as a separate topic.